1. Field of the Invention
The present invention relates to an optical instrument having a lens group, and capable of driving this lens group in an optical axis direction, and to a control method for an optical instrument.
2. Description of the Related Art
In an optical instrument having a photographing lens etc., it has been proposed to carry out positional control of a lens group by controlling a lens group with an actuator instead of a cam tube etc. For example, Japanese Patent laid-open No. 2007-286225 (hereafter referred to as patent publication 1) discloses providing a plurality of photosensors for a single lens group in order to carry out position control of the lens group, and determining a specific position of the lens group based on output of these photosensors.